"[Kant] believed, as did almost everyone of his day who understood it, that the new science of the Seventeenth Century had set mankind on the highroad towards understanding the universe. He supposed, as again did others, that scientific knowledge was uniquely certain, and that what gave it its unique certainty was that it consisted of a combination of two processes neither of which admitted of error. The first was direct observation, not just on one occasion by one person, but observations repeated systematically by that person and then checked systematically by others. The second was logical deduction from observationstatements which had been arrived at in this way. So he took the whole of science to consist of things that were known infallibly to be true either because they had been directly observed -- and if appropriate measured -- under controlled conditions on many different occasions by trained and competent observers, or because they followed by logical necessity from what had been thus observed. Science, in other words, consisted entirely of immediate observation plus logic, and these were two processes which, if carefully and properly executed, yielded the highest level of certainty that there could be." Bryan Magee, Confessions of a Philosopher, pp.141-142 "Those who have taken upon them to lay down the law of Nature as a thing already searched out and understood, whether they have spoken in simple assurance or professional affectation, have therein done philosophy and the sciences great injury. For as they have been successful in inducing belief so they have been effective in quenching and stopping inquiry; and have done more harm by spoiling and putting an end to other men's efforts than good by their own." Francis Bacon: Novum Organum The wrong view of science betrays itself in the craving to be right; for it is not his possession of knowledge, of irrefutable truth, that makes the man of science, but his persistent and recklessly critical quest for truth. Sir Karl Popper The Logic of Scientific Discovery
Science never pursues the illusory aim of making its answers final, or even probable. Its advance is, rather, towards the infinite yet attainable aim of ever discovering new, deeper, and more general problems, and of subjecting its ever tentative answers to ever renewed and ever more rigorous tests. Sir Karl Popper The Logic of Scientific Discovery